Gas exchange and photosynthetic pigments in zucchini plants under cattle bio-fertilization and sources of nitrogen

Damiana Ferreira Da Silva Dantas,Ademar Pereira Oliveira,Naysa Flávia Ferreira Nascimento,Ronaldo Nascimento,Tony Andreson Guedes Dantas,Lourival Ferreira Cavalcante

doi:10.33448/rsd-v9i11.8107

Abstract

Zucchini is traditionally used in human consumption, however, the scarcity of information, especially about fertilization and the physiological aspects of this crop, constitutes a major obstacle its cultivation and commercialization. The objective was evaluate the chlorophyll content and gas exchange under cattle bio-fertilization and different sources of nitrogen. The work was carried a randomized block experimental design was used in a factorial scheme 5 x 3 + 1 composed of five cattle bio-fertilizer concentrations, three sources of nitrogen and an additional treatment without nitrogen. The levels of chlorophyll a, b and total, liquid photosynthesis, transpiration, internal CO2 concentration, stomatal conductance, instantaneous water use efficiency, and instantaneous carboxylation efficiency were evaluated. The studied variables were influenced by the interaction between the concentrations of the cattle bio-fertilizer and the nitrogen sources, except for the chlorophyll b content and the instantaneous water use efficiency, which responded only to the nitrogen sources. Ammonium sulfate and urea increased increase the physiological variables evaluated. The combination of ammonium sulfate with bio-fertilizer promoted an increase in chlorophyll a, total chlorophyll, liquid photosynthesis, transpiration, internal carbon concentration, stomatal conductance, and instantaneous carboxylation efficiency. The cattle bio-fertilizer in the soil without nitrogen did not increase the physiological variables evaluated.

Highlights

Zucchini (Cucurbita pepo L.), in Brazil, it stands among the top ten vegetables of greatest production and economic value (Kumar et al, 2016), mainly in the Center and South regions of the country, and is traditionally used for human consumption, especially in the northeast.According to Purquerio et al (2019) the productivity of the crop is highly variable depending on the technology level and nutritional recommendation used
The use of organic matter in combination with mineral fertilization increases the absorption of macro and micronutrients by plants and improves the physical, chemical, and biological characteristics of the soil, which results in increased plant growth and development
Among the sources of organic matter to be used, the cattle bio-fertilizer, the final residue of the fermentation of organic compounds that contain living or latent cells of microorganisms, when applied to the soil contributes to a balanced supply of nutrients (Silva et al, 2019)

Summary

Introduction

Zucchini (Cucurbita pepo L.), in Brazil, it stands among the top ten vegetables of greatest production and economic value (Kumar et al, 2016), mainly in the Center and South regions of the country, and is traditionally used for human consumption, especially in the northeast. The second most required nutrient for vegetables, is an essential nutrient, determinant for plant production and development, is found in the soil in organic and inorganic forms, being absorbed by plants mainly in the form of nitrate (NO3-) and ammonium (NH4+). It is the constituent of many organic compounds, nucleic acids, and proteins, indispensable for the synthesis of chlorophyll and, in the photosynthesis process (Taiz et al, 2015). This study aimed to evaluate the chlorophylls content levels and gas exchange in zucchini plants under cattle bio-fertilization and different nitrogen sources.

Results and Discussion

Nitrate sulfate

Calcium Ammonium nitrate sulfate a